Grinding apparatus



Aug. 8, 1967 Filed March 30, 1966 FIG. I.

N- H. HUTTON GRINDING APPARATUS 2 Sheets-Sheet 1 ATTORNEYS 1967 N. H. HUTTON 3,334,451

GRINDING APPARATUS Filed March 30, 1966 2 Sheets-Sheet 2 FIG. 2.

lA/VEW'TO/PS NORMA/V H0554 r70 HUTTO/V A TTOR/VEYS 3,334,451 GRINDING APPARATUS Norman Horatio Hutton, 85 Wick Hall, Furze Hill, Hove 2, Sussex, England Filed Mar. 30, 1966, Ser. No. 538,635 Claims priority, application Great Britain, Apr. 9, 1965,

9 Claims. (Cl. 51267) This invention relates to the grinding of metals, ceramics and other materials and has for its object to provide improved means applicable to the hood or shroud in which a rotary grinding element is mounted, such means being designed to facilitate the removal of waste material formed by the grinding operation, to ensure constant penetration of the surface of the grinding element by a coolant liquid and to prevent rapid deterioration of the grinding element due to disintegrated particles becoming embedded in its surface.

In my prior Patent application No. 297,279, now Patent No. 3,256,647, issued June 21, 1966, I have described an arrangement wherein additional means are provided for introducing coolant liquid to the interior of the hood of a grinding element at a point remote from the workpiece and a deflector element also disposed within the hood to ensure that as the diameter of the grinding element decreases a substantially constant space is maintained to which coolant liquid is introduced.

The present invention is designed to provide positive means for forcing the coolant liquid into contact with the surface of the grinding element during the passage of the coolant through the hood or shroud thereby enabling the forces generated centrifugally by the grinding element to impart and maintain velocity in the coolant and ensure its maximum utilisation throughout the area of grinding element surface enclosed by the hood or shroud.

According to the invention a grinding apparatus comprising a rotatably mounted grinding element having an abrasive peripheral surface, a hood partially enclosing the said grinding element and additional means for introducing coolant liquid to the interior of said hood at a point remote from the workpiece is characterised by an adjustably mounted deflector element through which coolant is introduced to the surface of the grinding element and whose inner surface is formed or provided with a number of vanes, ridges or blades arranged to deflect the coolant back onto the grinding element repeatedly without material loss of velocity.

Reference will now be made to the accompanying drawings which illustrate by way of example a construction according to the invention and in which:

FIG. 1 is an elevation showing the application of the invention to a grinding wheel,

FIG. 2 is a view on an enlarged scale and partly in section of the deflector element and the adjusting means therefor, and

FIG. 3 is a bottom plan of the deflector element.

In the construction illustrated a rotary grinding wheel 1 is disposed within a housing or hood 2 which partially encloses the said Wheel. Known means are provided external to the hood 2 for bringing a workpiece 3 into contact with the grinding surface and also for directing coolant liquid onto the area of contact in known manner by a jet 4.

An inlet 5 for coolant liquid is also arranged within the hood 2 for directing such liquid onto the surface of the grinding wheel 1 over an area remote from the position of the workpiece. It has been found in practice that as the diameter of the grinding wheel becomes reduced by wear, the additional inlet of coolant liquid becomes progressively less effective in producing the conditions within United States Patent 0 ice the hood necessary for adequate removal of debris and penetration of the grinding surface by the coolant liquid. To deal with this difliculty and further promote general efficiency the present invention provides a deflector in the form of a plate 6 of curvature concentric with that of the grinding wheel and hood within which the deflector is adjustably mounted so that it can be moved at intervals to maintain a position in predetermined concentric relationship with the grinding wheel as the diameter thereof gradually decreases during use. The deflector 6 is carried at the end of a coolant supply conduit 7 which terminates in the inlet 5 within the hollow deflector 6. The conduit 7 passes through a socket 8 fixed at the centre of a curved plate 9 clamped to the exterior of the hood by bolts and nuts 10 and sealed by means of a gasket 11. The conduit 7 which occupies at all times a position radial to the hood, is movable through the socket 8 to enable the position of the deflector 6 relatively to the surface of the grinding Wheel 1 to be adjusted, a clamping screw 12 being provided in the socket 8 for securing the conduit 7 in the required position of adjustment. The conduit 7 is connected to a reservoir 13 (FIG. 1) and a pump 14 for maintaining the coolant supply. Coolant liquid passes from the supply conduit 7 to the interior of the deflector 6 from which it makes its exit through a number of slots 15 formed in the inner surface 16 of the deflector, these slots extending in directions transverse to the direction of rotation of the grinding wheel as shown in FIG. 3.

The inner surface 16 of the deflector is also formed or provided with a number of closely arranged parallel ridges or blades 17 disposed transversely of its length and each ridge or blade has one surface 18 inclined inwardly in the direction of rotation of the grinding wheel indicated by the arrow in FIG. 1. The edges of the ridges 17 are preferably slightly flattened.

According to the present invention the position of the deflector plate is adjusted by utilising the devices shown in FIG. 2. In this arrangement a collar 19 is disposed around the conduit 7 and is provided with a clamping screw 26 To set the device for operation and to determine the clearance between the inner surface of the deflector 6 and the grinding wheel 1 the collar 19 is first slackened and withdrawn clear of the sleeve 8. The clamping screw 12 is then slackened and the deflector pushed into contact with the surface of the grinding wheel and the screw 12 again tightened. The collar 19 is next moved into contact with the outer end of sleeve 8 and the clamping screw 20 tightened. The clamping screw 12 is next slackened and the conduit 7 drawn outwardly from the sleeve 8, a gauge 21 being then inserted between the end of sleeve 8 and the collar 19. The collar 19 is again moved inwards to clamp the gauge 21 firmly between the collar and sleeve 8 and both clamping screws 12 and 20 tightened. The inner surface of the deflector 6 is thus spaced from the surface of the grinding wheel by a distance equal to the thickness of the gauge 21, the initial clearance being between one sixteenth and one eighth of an inch according to the character of the grinding wheel and the metal or other material to be ground.

In most instances the wear on the grinding wheel is from one sixteenth to one eighth of an inch per normal working period necessitating readjustment in the position of the deflector in the manner above described.

In the operation of the arrangements above described during grinding, the coolant liquid issuing through the slots 15 in the deflector impinges on the surface of the grinding wheel 1 and rebounds therefrom onto the ridges or blades 17 under the influence of the centrifugal force generated by the speed of rotation of the wheel. The form and disposition of the blades causes the coolant liquid to be returned towards the surfaces of the wheel without .9 substantially losing its imparted velocity, being repeatedly forced onto the wheel surface by reaction. The coolant is thus retained between the deflector and the grinding wheel for repeated active impact on the surface of the wheel until it passes beyond the confines of the hood carrying with it debris loosened by its impacts which would otherwise remain in the interstices in the rough surface of the wheel or become adherent to the inner surface of the hood.

The three slots 15 as shown in FIG. 2 through which coolant is discharged onto the grinding wheel may vary in dimensions, number or disposition depending on the design of the deflector 6 which depends on the character of the grinding wheel and the machining requirements. The slots are so particularly arranged asv to extend transversely over the abrading surface of the grinding wheel and are of such dimensions as to enable the pump 14 to deliver a copious supply of coolant under suflicient pressure to fulfill the purposes of the invention. The disposition of the slots 15 ensures that coolant lost by expulsion from the space between the deflector 6 and the grinding wheel is continually replaced.

The operations described enable the surface of the grinding wheel to be adequately cooled and its surface to be preserved in efficient grinding condition over a longer period than has hitherto been possible. This increase in the operative efliciency of the grinding wheel also prevents overheating, distortion or deterioration of the workpiece.

What is claimed is:

1. A grinding apparatus comprising a rotatably mounted grinding element having an abrasive peripheral surface, a hood partially enclosing the said grinding element and means for introducing coolant liquid to the interior of said hood at a point remote from the workpiece characterised by an adjustably mounted deflector element through which coolant is introduced to the surface of the grinding element and having an inner surface facing and spaced from the periphery of said grinding element, said deflector element being provided with a plurality of ridges extending inwardly from said inner surface and being arranged transversely over said grinding element to deflect the coolant back onto the grinding element repeatedly without material loss of velocity.

2. A grinding apparatus according to claim 1 wherein the said deflector element is carried by the inner end of a coolant supply conduit which is adjustably mounted in the hood for the purpose of moving the deflector element and maintaining it in substantially constant relationship with the grinding element.

3. A grinding apparatus according to claim 1 wherein the deflector element comprises a hollow curved plate with a number of outlets on its inner side for effecting the discharge of coolant onto the surface of a grinding element.

4. A grinding apparatus according to claim 3 wherein said ridges are parallel and wherein each ridge has one surface inclined inwardly in the direction of rotation of the grinding element.

5. A grinding apparatus according to claim 2 wherein the coolant supply conduit passes through a socket mounted on the exterior of the hood and wherein a clamping device is provided for securing said conduit and the deflector element in any desired position of adjustment.

6. A grinding apparatus according to claim 5 including a collar mounted on the supply conduit externally of said socket and wherein means are provided for clamping said collar in position on said conduit, a gauge disposed between the collar and socket, said socket cooperating with said gauge to determine the spacing between the deflector plate and grinding wheel.

7. The grinding apparatus defined in claim 1 wherein said deflector element comprises a hollow, curved plate adapted to be mounted on the inner end of a coolant supply conduit and having on its inner surface a number of slots through which coolant liquid is adapted to pass onto the surface of a grinding wheel, said ridges being disposed between said slots.

8. A grinding apparatus comprising a rotatably mounted grinding wheel, a hood partially enclosing said grinding wheel, a coolant supply conduit adjustably mounted in a socket on said hood, a hollow curved deflector plate mounted on the inner end of the supply conduit and in concentric relationship with the peripheral surface of the grinding wheel, slots in the inner surface of the deflector plate through which coolant introduced through the supply conduit passes onto the periphery of the grinding wheel, a number of ridges on the inner surface of the deflector plate between the slots each ridge having one surface inclined inwardly in the direction of rotation of the grinding wheel, means for locking the conduit and deflector plate in the required position of adjustment relatively to the grinding wheel and means for determining the position of the deflector plate in relation to the grinding wheel.

9. The grinding apparatus defined in claim 1 wherein said ridges are disposed in parallel spaced apart relation and are each continuous from one side of the deflector element to the other side thereof.

References Cited UNITED STATES PATENTS 385,666 7/ 1888 Hadley 51-267 2,803,098 6/1955 Downing et al 51-273 3,123,951 3/1964 Kuris et al 51262 3,256,647 6/1966 Hutton 51-267 FOREIGN PATENTS 701,220 1/ 1941 Germany.

ROBERT C. RIORDON, Primary Examiner.

ADDISON MATHEWS, Assistant Examiner. 

1. A GRINDING APPARATUS COMPRISING A ROTATABLY MOUNTED GRINDING ELEMENT HAVING AN ABRASIVE PERIPHERAL SURFACE, A HOOD PARTIALLY ENCLOSING THE SAID GRINDING ELEMENT AND MEANS FOR INTRODUCING COOLANT LIQUID TO THE INTERIOR OF SAID HOOD AT A POINT REMOTE FROM THE WORKPIECE CHARACTERISED BY AN ADJUSTABLY MOUNTED DEFLECTOR ELEMENT THROUGH WHICH COOLANT IS INTRODUCED TO THE SURFACE OF THE GRINDING ELEMENT AND HAVING AN INNER SURFACE FACING AND SPACED FROM THE PERIPHERY OF SAID GRINDING ELEMENT, SAID DEFLECTOR ELEMENT BEING PROVIDED WITH A PLURALITY OF RIDGES EXTENDING INWARDLY FROM SAID INNER SURFACE AND BEING ARRANGED TRANSVERSELY OVER SAID GRINDING ELEMENT TO DEFLECT THE COOLANT BACK ONTO THE GRINDING ELEMENT REPEATEDLY WITHOUT MATERIAL LOSS OF VELOCITY. 